Optical components are tested after they are manufactured to determine whether connectors at ends of the components can make a reliable optical connection. A reliable optical connection typically means a connection that has associated with it less than a threshold amount of loss of optical power (e.g., less than a 0.2 dB loss).
Currently, optical testing is performed on an overall throughput loss basis. An example test setup 10 is illustrated in FIG. 1, and includes a transmitter 12 that transmits a signal having a known power and a receiver 14 that can detect power transmitted on opposite sides of an optical device 16 under test. The optical assembly 16 to be tested is interconnected between the transmitter 12 and the receiver 14, at connectorized ends 18a, 18b. The difference in optical signal strength at each end of the optical device 16 corresponds to the difference between transmitted power and received power.
In one example of such a test, optical equipment 16 (e.g., including some type of connectorized fiber, such as a splitter or other optical equipment) is tested by injecting a signal having a known power from the transmitter 12 to the receiver 14. The loss in power due to the tested system (e.g., the splitter) is referred to as insertion loss of the optical device. This loss primarily occurs at the leading edge connector (e.g., connector 18a), because the receiver includes a photodetector rather than a second fiber-to-fiber junction. The amount of power reflected back to the transmitter (at which a receiver can also optionally be placed) is referred to as return loss. To obtain both the insertion loss and return loss in an arrangement such as that shown in FIG. 1, the transmitter 12 and receiver 14 are placed at opposing sides of the optical device 16, and losses are measured; then, the positions of the transmitter 12 and receiver 14 are reversed, and the optical device is retested.
Use of this type of test setup does not work well with optical devices that are not connectorized at both ends. This is because the test arrangement typically involves connecting transmitting and receiving equipment to both an input and output side of the optical assembly. So, for devices that are not sold preconnectorized at both ends, temporary connectors must be installed onto the otherwise non-connectorized end. These temporary connectors, and the permanent connectors otherwise included in such optical devices, are error prone and are tested on a trial and error basis until a successful reading is achieved. Additionally, the location of an error within a particular optical device cannot be detected using such an end-to-end arrangement; only overall loss can be detected.
Therefore, in existing systems there are a large number of possible sources of error in forming a functional optical device with acceptable insertion loss and return loss, and testing is very time consuming due to the requirement of inserting temporary connectors and testing each device multiple times.